As for the argument for sparing Chackmon, come on guys, can't you find it in yourselves to spare the guy, he is crying and is in terror, sure it may backfire, but we should at least try.
How about we offer to guard him until we reach a Host prison where he won't be our responsibility anymore, I mean if we are the ones to guard him, his chance of escaping will drastically reduce, and it might stop him from getting killed by MagnaAngemon.
Seriously lets offer him a second chance, it's probably what Agnimon would have done and would be a heroic thing to do.